In addition to the RPC Client Access Service, Exchange 2010 introduces a new logical structure to the Exchange organization: The Client Access server array. When a client Access server array is defined in an Active Directory site, the array acts as a single point of contact for all client connections in that Active Directory site.
A client Access server array can include one or many client access servers, so a client Access server array can do a redundancy solution.
After a client Access server array is defined in an Active Directory site, all client access servers in that Active Directory site automatically become part of the Client Access server array.
Each Active Directory site can have a client Access server array, and it is worth noting that the Client Access server array itself does not provide load balancing and still requires a separate load balancing solution. Currently popular load balancing solutions are based on two categories of hardware and software, the hardware is currently representative of the product has F5 and Citrix NetScaler, software has NetScaler VPX, of course, the simplest soft load balancing solution is Windows Server The Network Load Balancing (NLB) that comes with it. Let's start by saying why Microsoft is going to elicit a client Access server array (the Customer Access server array):
First, why use CAS array?
The Client Access server array, in addition to being part of high availability, has another important reason to recommend creating a client Access server array, even if there is only one client Access server in the organization. Because the Client Access server array is created, the client connects through the virtual name of the client Access server array instead of directly connecting to the fully qualified domain name (FQDN) of the individual client Access server. If you need to replace a client Access server or add another client Access server in an Active Directory site, you do not have to update the configuration file on the client.
The following is a brief introduction to adding Windows-brought Load Balancer feature and creating a Client Access server array (no in-depth parsing, there are many similar articles on the web to search related topics on their own)
Ii. Installing and configuring NLB
1. Installing the NLB Component
On the CAS server, open PowerShell and execute the following 2 commands:
2. Configuring the NLB Component
A lot of detailed steps on the web, according to the wizard step-by-step do not have a problem, or refer to the Official document: Create a new Network Load Balancing cluster
3. Configure DNS to parse the cluster FQDN of the CAS array
Do not ignore this step, create a record in DNS, point to the cluster IP address.
Iii. Creating a CAS array
In fact, it is very simple, with 1 commands:
New-clientaccessarray-name "BJ CAS Array"-fqdn "bj-cas.lab.net"-site "BJ"
Iv. requesting a certificate for Client Access services
The detailed steps on the web are many, not much to say. There is an empirical suggestion, write more "user alternate name" at a time, the FQDN of the CAS array, the public OWA domain name, and so on, so as not to update the certificate every time.
V. Update Database Rpcclientaccessserver Properties
This step is important. When the CAS array is created, each new database points to the FQDN of the CAS array, but the old database does not, so it needs to be updated. The command is as follows:
Set-mailboxdatabase "Db_name" –rpcclientaccessserver CASArray.contoso.com
To update all databases in bulk:
Get-mailboxdatabase | Set-mailboxdatabase-rpcclientaccessserver bj-cas.lab.net
This is why when you configure an Outlook MAPI client, the name in the server is the FQDN of the CAS array that was filled in, and the name is changed back to a specific CAS server name.
The method of updating the database Rpcclientaccessserver property also applies to redirecting the user to a good CAS server.
On the Client Access server array in Exchange 2010 Clientaccessarray